1. Field of the Invention
The invention relates to a method and a device for feeding layers of tobacco to an intermediate reservoir.
The invention relates more particularly to a method and device for feeding layers of tobacco to a box for cut ribs and stems.
2. Description of the Related Art
Tobacco products, especially cigarettes, are typically composed of many different grades of tobacco and thus for the quality of these tobacco products a consistent fidelity in blend is substantial on the basis of the large amounts of tobacco to be processed in preparing the tobacco, so that each and every cigarette contains a constantly homogenous tobacco blend.
If, for this purpose, a proportion of a certain grade of tobacco necessary for a specific blend were to be fed directly to the blending box from a silo, layers of tobacco would result in the blending box greatly differing in homogeneity to such a degree that the wanted homogeneous quality of the finished tobacco product would be unfavorably influenced.
That is why it is important in satisfying the basic requirement that the large blending boxes as known in the tobacco industry are filled with differing grades of tobacco in such a way that the various grades of tobacco are deposited by layers in such a blending box so that the lengths of the individual layers correspond to the length of the blending box.
Then, from the tobacco mass thus formed, vertical portions are removed containing tobaccos of various layers and thus various grades of tobacco to generate a homogenous blend of tobacco.
Thus, various devices have been developed, intended it assure the consistent stratification in such blending boxes, see e.g. DE 20 24 513 A, U.S. Pat. No. 4,619,576 and U.S. Pat. No. 3,811,585.
A further problem associated with such a blending box is that the tobacco needs to be fed equally apportioned for further processing. For this purpose it is usually such that at the outlet end of the blending box so-called sweeper rakes are installed which acts as rotating spiked shafts and which are provided with spikes to tear the vertical tobacco portions from the face wall of the tobacco mass in the blending box. This allows this particular tobacco to be supplied for further processing. However, discharging the layers of tobacco in this way from the blending box greatly stresses the tobacco, degrading it accordingly. This applies in particular to cut tobaccos having a high moisture content which in critical bulk heights and lengthy storage periods tend to pack and clump so that discharge by means of sweeper rakes results in heavy detriment to qualify.